Circuit breaker



July 25, 1933. R M STAFFORD 1,919,385

G IRCUIT BREAKER Filed June 23, 1930 2 Sheets-Sheet l Z5 INVENTORstafiofi 1 c ATT o NEYfi f July 25, 1933. R. M. STAFFORD C IRCUITBREAKER Filed June 23, 1930 2 Sheets-Sheet 2 @CQa/Jfi ATTORNEY5 HWENTOR{by M. :SLCL-fi BY 0 Patented July 25, 1933 UNITED STATES PATENT OFFICEROY M. STAFFORD, OF BEAUMONT, TEXAS, Assrcnon To STAFFORD ELECTRIC GAUGECORPORATION CIRCUIT BREAKER Application filed June 23,

My invention relates to fiuid level indicators by means of which thefluid. level in tan -3 or similar containersmay be read on an indicatorat some distance from the tank. The present invention relatesparticularly to the circuit breaker positioned at the tank through whichelectrical impulses are transmitted to the distant indicator.

It is an object of my invention to construct a simple type of circuitbreaker of this character which may-be positioned on the tank itself andconnected with the tank in such manner that no leakage of gas from thetank may escape.

It is also an object to providea switch-opcrating mechanism which may bemounted in an oil bath for effective lubrication and in which there isno danger of a spark whereby the gas or oil may be ignited.

The device is intended particularly for use in oil tanks whereinpetroleum is stored before use and the general purpose of the inventionis to provide a circuit breaker for use with an indicator which may behoused in a small and compact casing and which will be particularlyaccurate and reliable in its action.

Referring to the drawings herewith, Fig. 1 illustrates a side view of myinvention mounted upon the top of a tank with certain parts being shownin section for greater clearthe structure shown in my prior applicationfor Patent No. 375,944, filed July 5, 1925, and co-pending herewith. Theinvention herein resides in the modification of the device set out inthe prior application whereby '-.the' circuit breaker may be positioneddirectly upon the tankand wherein provision is made for preventing theescape of gas from said tank.

lVith reference particularly to Fig. 1, I have shown. the device asmounted upon the top or roof 1 of a sheet metal tank of the usualconstruction employed in oil storage work. The deviceis housed within anouter casing 2, the walls of which are made tight to form a containerforoil shown at 3 there- 1930. Serial NO. 463,298.

in. The casing is mounted upon a short post or pedestal 4L secured tothe upper wall of the container in any desired manner. The shape of thecasing or container is formed to provide a shoulder 5 midway of theheight of the casing upon which the frame 6 of the mechanism may besupported. The upper end of the tank is closed by a cover plate 7,through which I have provided openings to receive pipes 8 and 9 throughwhich the controlling float and weight connections may pass.

The supporting frame 6 of my device is preferably a skeleton frame metalapproximately rectangular in outline and shaped to fit within thecasing. The structure of this frame will be understood more clearly fromMounted upon this frame intermediate the ends thereof is a cross shaft10, which is supported for rotation upon the frame. 011 one end of theshaft is formed a toothed wheel or gear 11, the periphery of which isformed with teeth of the proper size to be engaged by an operating chain12 shown in Fig. 1. This wheel is fixed to the shaft, which is adaptedto rotate therewith.

Mounted on said frame and directly above the shaft 10 is a shaft 13,also rotatable on its bearings and operatively connected with the shaft10 through a small gear 1 L thereon, mounted on said shaft13 and adaptedto mesh with a, larger gear 15 on said shaft 10 and positioned betweenthe wheel 11 and the inner frame member.

Mounted on the upper shaft 13 are two rotating wheels 16 and 17. Thesetwo wheels are loose upon the shaft and are ordinarily idle thereon.They may be connected for rotation with said shaft, one in one directionand the other in the opposite direction, by means ,of a ratchet and pawlarrangen'rent which will presently be described. Each of the wheels 16and 17 have a wide groove cut in the periphery thereof and at spacedintervals along the said groove are transverse pins 18 adapted tocontact with the lever arms 19 and 20 respectively.

Between thetwo wheels 16 and 17 is the disc 21, said disc being ofmaterially smaller diameter than are the two wheels 16 and 17 and isfixed to the shaft so as torotate therewith. Each of the wheels 16 and17 has an is formed into a ratchet wheel having teeth 24 thereon adaptedto be engaged by a pawl upon the disc 21. Said pawl engages the ratchetin such manner as to cause the movement of the hub and the adjacentwheel when said disc is rotated in one direction. The opposite wheel isengaged by a similar pawl 24 and this pawl is so, arranged as to allowthe rotation of the other wheel, but in an opposite direction to that ofthe first wheel. In this manner the rotation of the shaft 13 and thedisc 21 in one direction will rotate the wheel 16. The rotation of theshaft and disc in the opposite direction will rotate the wheel 17.

Each of the wheels is held against rotation in a direction opposite tothe one in which it is turned through the shaft 13 by a pawl 25 engagingwith a ratchet 26 on the hub 22, the arrangement of the pawl 25 beingshown best in dotted lines in Fig. 3, and it will be Seen that theratchet wheel 26 on the hub 22 is engaged by the pawl 25 to prevent itsmovement in one direction but permitting its movement in the oppositedirection. Said pawl is held against the ratchet wheel by a spring 27Thus it will be seen that the rotation of the shaft 13 in one direction,due to .its connection with the shaft 10, upon which the wheel 11 ismounted, will rotate one of the discs when said wheel is rotated in onedirection and will rotate the other disc when said wheel is rotated inthe opposite direction, and that the backward movement of the wheels 16and 17 will be prevented by the pawls 25 engaging with the ratchetwheels 26 on the outer hubs 22 of said wheels.

The two wheels 16 and 17 engaging with the two levers 19 and 20 serve totrip said 'levers so as to operate electric switches connected in acircuit with an indicator not shown- The circuit in which the switchesare mounted is made or broken by the tripping of the lever. Thus whenthe shaft is rotated in an anti-clockwise direction, as seen in Fig. 3,the pins 18 will successively engage the lever arm 20. thus moving thearm downwardly and raising the arm 28 on the opposite end of the lever.This arm has a weight 29 thereon and its extremity is formed with an oening therein to receive a pivot pin 30 by means of which it isconnected with a rocking arm or rod 31.

The upper end of said arm has a head thereon, the outer side of which isformed with a shoulder 33, which is adapted to engage with the arm 34 ata point shown at at the right of Fig. 3. It will be seen'that the head32 is adapted to move within a slot in the arnr 34, the shoulder 33engaging upon the inner end of the slot at 35. The

* arm 31' is inclined outwardly so as to normally hold the shoulderedface 33 against the end of the slot at 35..

The arm 34 is pivoted between its ends upon a shaft 36, mounted on theupper end of a post 37. It has a weight 38 on its outer end which tendsto hold said end downwardly in the position shown in Fig. 0. lVhen inthat position the arm is supported upon an adjustable bolt or pin 39mounted in an arm 40 upon the post 37. Adjacent the shoulder 35 upon thearm 3% is an upwardly projecting stop member ell, said stop member beingslightly spaced from the shoulder 35. Thus it will be seen that when thelever 20 is moved by the rotation of the wheel the arm 31 will be movedupwardly and as it is moved upwardly it will drop toward the shoulder 35upon the arm Sal and bear against the stop member 41. 11011 the pin 18upon the wheel has passed the lever arm 20 it will move backwardlythrough the force of the weight 29 and the arm 31 will drop downwardly,engaging the shoulder 35 and rocking the arm 31 on its pivot. As soon asthe said arm is rocked into what is practically a. horizontal positionthe upper end 42 of the head 32 will engage against the stop member l]and be pushed laterally out of engagement with the shoulder 35 and thearm 31 will drop back into the position shown in the drawings.

Mounted on the rock arm 3 1 is a mercury contact switch 4-3. This switchis of common construction well known in the art. There are contactpoints at each end within a closed tube which are connected toconducting wires 15 leading to a main. conducting line shown generallyat 4-6 in Fig. 2. These con tact wires are spaced apart and are adaptedto be connected by a quantity of n'iercury shown at 17 in Fig. 3. Thuswhen the arm 34 is rocked by engagement with the arm 31 the n'iercurywill flow down into a horizontal position, making contact with both ofthe wires in thecircuit, thus closing the same and energizing the magnetor similar means at the indicator. This type of switch is not includedas a novel feature in applieants invention.

The circuit breaker thus provided is actuated by connectidn with a float48 shown in Fig.1 and resting upon the upper surface of the liquid 49 inthe tank. Said floathas a flexible line or chain shown at 12, whichpasses upwardly through a tubular support 51 and about a pulley 52 abovethe upper end of the casing 2. It passes from said pulley downwardlyinto the casing. A short pipe 53 projects downwardly through. the cover7 in the casing and extends below the level of the liquid 3 in the saidcasing. The pulley or sheave 52 is enclosed within a. fluid tighthousing 54:, so that gas which may escape upwardly from the tank throughthe tubular support51 may obtain access to the housing 54 for the pulleybut may not escape into the casing 2 because of the fact that the lowerend of the pipe 53 is submerged, making a seal against the gas at thatpoint. i

The chain which forms a flexible line passes around the lower side ofthe toothed wheel 11 and upwardly around a second pulley within acasingfi l and back down through a tubular support 51 into the tank. Aweight indicated at 55 on the opposite end of the line tends to hold thechain taut about the pulleys and the wheel as shown in Fig. 1.

The operation of my device will now be clear. The float 4L8 resting uponthe liquid will be moved vertically, corresponding wit-h the level ofthe liquid in the tank. If the liquid is being removed from the tank thefloat will gradually lower with the level of liquid, thus rotating thetoothed wheel 11 in a clockwise direction, as seen in Fig. 1, and thismovement of the wheel will, through the rotation of the shaft 10, causea rotation of he shaft 13, thus moving the proper wheel 16 or 17 so asto actuate the proper lever 19 or 20, thus rocking the proper arm 34 andthus closing the circuit at that point and energizing the circuit insuch manner as to record the movement upon the indicator.

The advantages of this structure lies in fact that the larger part ofthe mechanism may be submerged in oil, thus keeping the bearingsproperly lubricated and keeping them free from material which might tendto clog the mechanism. It will e seen from Fig. 1 that I do notcontemplate having the level of liquid high enough to submerge theswitch member. It is unnecessary when the n'iercury type of contactmember is employed to allow for a spark between the terminals. Theswitch is entirely enclosed. and there therefore no danger of ignitingthe gas which may find access to the casing 2. Fur hermore, thearrangement by means of which the rocker arm 34 is operated to close thecircuit and to again release said rocker arm provides an operatingdevice which may work rapidly without danger of failing to registerthrough the proper closure of the electric circuit.

The device therefore, of simple construction and adapted to be housedwithin a smaller casing which may be supported upon the upper end of thetank. A large part of the usual mechanism connected with devices of thiskind are hence dispensed with.

What I claim as new is: v

1. A liquid containing tank having an upper cover plate thereon, acasing mounted on said plate, a wheel mounted for rotation in saidcasing, a float in said tank, a flexible line attached at one end tosaid float and passing out of said tank about said wheel and back intosaid tank, a weight on the other end of said line, a circuit breaker operated by said wheel, said casing being adapted to contain a liquidlubricant, and tubes through which said line is passed to said casing,the ends of said tubes bein submerged whereby a seal is provided againstthe escape of from said tank.

2. it. circuit breaker for an oil tank including a casing, a frametherein, a shaft in said frame, means to rotate said shaft responsive tochanges .in liquid level in said tank, a pair of wheels mounted looselyon said shaft, a disc fixed on said shaft, means on said disc to engageand rotate one of said wheels when said shaft is rotated in one direccion, a lever mounted for engagement with said wheel, a rod on oneend of said lever, a rocking arm pivoted adjacent said rod, a switch ons: id arm, and means on said rod to engage and rock said arm when saidlever is engaged by said wheel.

3. A circuit breaker for an oil tank including a casing, a frametherein, a shaft in said frame, means to rotate said shaft responsive tochanges in liquid level in said tank, a pair of wheels mounted looselyon said shaft, :1 disc fixed on said shaft, means on said disc to engageand rotate one of said wheels when said shaft is rotated in onedirection, a lever adjacent each of said wheels, means on said wheel toengage'and rock said lever, a rocking arm pivoted upon a post adjacentsaid lever, a mercury switch thereon, a rod connected with said leverand adapted. to engage and rock said arm'when said lever is rocked.

i. A circuit breaker for liquid level indicators including a liquidcontainer, a casing thereon, a shaft rotatable in said casing, means onsaid shaft to rotate the same in response to changes in liquid level insaid container, a rocking arm, a mercury contact switch thereon, a leveradjacent said shaft, means on said shaft to engage said lever when saidshaft is rotated in one direction, and a rod on said lever engaging saidarm to cause a rocking of said arm to close said switch when said leveris actuated.

A circuit breaker for liquid level indicators including a liquidcontainer, a casing thereon, a shaft rotatable in said casing, means onsaid shaft to rotate the same in response to changes in liquid level insaid container, a rocking arm, a mercury contact switch thereon, a leveradjacent said shaft, means on said shaft to engage said lever when saidshaft is rotated in one direction, a red on said lever projectingthrough a slot in said arm, a shoulder on said rod engaging said arm,when said lever is moved, and means to disengage said shoulder from saidarm when said switch has been closed.

ROY M. STAFFORD.

